When I was a kid we occasionally played a game called Space Monkey, otherwise known as the "Hey, wanna faint?" game. The game, if it can be called a game, involved hyperventilating for several seconds and then holding your breath while your friend bear-hugged you from behind and lifted you off the ground. When your friend put you back down the world swam around you and sensations of perspective and gravity were temporarily suspended. Up became down, down became up and the next thing you knew you were lying on the ground exclaiming "Wow... Neato!"

The game of Space Monkey employed an effect called the Valsalva maneuver, which by means of intrathoracic pressure, compressed our superior and inferior vena cava. This reduced blood flow to the heart which in turn, reduced blood output from the heart. The reduced bloodflow to the brain induced a form of hypoxic euphoria which created the aforementioned sensations. My parents were not big fans of the practice and when they found out they issued a strict edict against it, backed up by the threat of corporal punishment (this was in the days when beating children was de rigueur). It was a potentially dangerous game but my parents needn't have bothered getting all hardass about it. The euphoric sensations were generally followed by nausea and headaches. And once you've done it a few times you're kind of in "been there, done that" territory. After a while the only thrill the game offered was to watch some neophyte collapse to the ground exclaiming "Wow... Neato!"

Hypoxic euphoria can occur whenever the brain is deprived of an adequate supply of oxygen. Drowning swimmers often report feelings of elation before they lose consciousness. D.E. Harding wrote his inspired essay "On Having No Head" based on revelations induced while in an oxygen deprived state during a high-altitude mountain climb. There is also speculation that the phenomenon of near-death-experiences (NDEs) is caused in part by the brain's reaction to lack of oxygen.

No one knows the precise reason why a lack of oxygen would give rise to these sensations. Neuroscientists have speculated that the euphoria is a side effect of what is known as the "glutamate cascade" that occurs when brain cells die. Essentially it goes like this: Without oxygen, brain cells die... quickly. As they die, a flood of glutamate is released. To prevent this glutamate overload from destroying other brain cells, the brain releases a receptor blocker to prevent the uptake of glutamate in the synaptic gap between cells. It is these blockers that give rise to the sensations of euphoria/God/peace, love, understanding and "Wow...neato!"

Space Monkey is the only time I've flirted with oxygen deprivation as a source of fun. By late adolescence I'd discovered drugs, booze and sex and that seemed to be enough. But a subclass of my contemporaries took the game to a whole new level. Specifically they added hypoxic euphoria to sexual euphoria and came up with something that, if those that practice it are to be believed, is greater than the sum of its parts. Call it "spanking the space monkey." Now personally, I can't imagine anything less erotic than prolonged oxygen starvation (ever since my brother trapped me under a bed blanket when I was 10 I've had a phobia about suffocation). But apparently the attendant sensations of hypoxic euphoria - diminished ego controls, giddiness and exhilaration, enhance sexual sensations and orgasm intensity.

Autoerotic asphyxia (AEA), as the practice is generally known, typically involves strangling oneself while masturbating. The most common method of strangulation is by means of a single ligature in the form of a noose or slip-knot around the neck, although another favorite is masturbating with a plastic bag over one's head. If the timing is right, one achieves orgasm just before one loses consciousness. The danger with autoerotic asphyxiation arises when one loses consciousness first. Depending on the apparatus used, the oxygen deprivation may continue after consciousness is lost and if this happens you're pretty much a goner.

Officially, more than 500 young men (they'll almost all under 30) die in America each year from AEA related accidents. The real number is thought to be much higher given the unwillingness of some parents to disclose the graphic nature of their son's death. Apparently, some parents would prefer people to think their son was suicidal rather than sexually adventurous. AEA may also be under-reported because parents and investigators are more often than not ignorant of AEA indicators. AEA fatalities often appear to be hanging incidents and are thus classed as suicides.

I know what you're thinking. "That wouldn't happen to me. I'd use a fail-safe. I mean come on, plastic bags... How stupid can people be?" And you'd have a point. It's possible that the reason that such a disproportionate number of AEA victims are teenagers is that teens are inherently stupid and reckless. There may well be millions of guys of all ages choking themselves while they choke the chicken; and we only hear about the few Darwin Award recipients who were too dim or impatient to come up with a workable fail-safe.

One possible fail-safe is to rig the apparatus so that constriction is a function of consciousness. Perhaps by slipping the rope through a pulley secured to the wall or ceiling and holding the other end. So if one loses consciousness, one let's go of the rope. But what if the noose is tied too tight to begin with? The rope may be slack but your windpipe is still constricted. And what if the rope gets jammed in the pulley? Your fail-safe only has to fail once and if it does you'll likely never know about it.

Ditto for those that rely on a friend or lover to rescue them. This may seem like a foolproof scheme but you're putting your life in the hands of someone else. Someone who may not - for any number of reasons - keep their end of the bargain. The last thing you want to see after the duct tape is placed over your mouth and nose is your "fail-safe" giving you the finger and walking out the door.

Chances are that every guy they cut down with his fist around his dick thought he had devised a "safe" way to do this. And not all victims are dim bulbs whose deaths served the interests of progressive evolution. Some smart guys have been found with their thickened tongues lolling from their mouths, including (reputedly) Michael Hutchence, front-man for the rock group INXS, cult cartoonist Vaughn Bode and Stephan Milligan, a British Member of Parliament. Likewise not all deaths are the result of stupidity or unseen failures in the fail-safe mechanism. Suffocation and orgasm in combination can place an unbearable strain on the heart.

As well, it's thought that some deaths are the result of what is known as the carotid sinus reflex. This happens when the choking action stimulates the carotid sinus which in turn sends impulses to the heart leading to cardiac arrest. There is speculation that this is the principle mechanism behind hanging deaths. (Hanging has always had something of a, er, stranglehold on execution-linked eroticism. William S. Burroughs, in Cities of the Red Night, wrote about men being hung and experiencing spontaneous ejaculation at the point of death.)

Even if you don't die from AEA, repeated episodes of hypoxia will result in irreversible brain damage. Remember, the euphoric sensation is a function of the brain's response to brain cell death! And what if something does go wrong? Death is never pretty but it doesn't get much uglier than the image that will greet your Mom when she walks into your room - a vision, I guarantee, that she'll carry with her for the rest of her life. All in all it's probably not worth all the risk just so you can end up on the floor exclaiming; "Wow... neato!"